This invention relates to a device for elimination of foam which forms on the surface of a liquid discharged from a vibrating finishing machine in which said liquid is a component part of the finishing solid particles containing medium.
The vibrating finishing machines with which this invention is concerned are of the kind described e.g. in the U.S. Pat. No. Re. 27,084 or German Pat. No. 1 288 947.
It has been common practice to use in the machines of this kind in addition to metallic pieces as finishing medium a mixture of solid granules made either of ceramic or plastic material such as polyesters in which abrasive material such as quartz is contained. Such granules are advantageously immersed in water which works both as cooling and washing medium and prevents formation of powder clouds, in addition to other working functions thereof. After termination of the required working cycles and after separation of the work pieces and the solid finishing granules from water, such water which contains abraded swarf forming particles is discharged as waste. Such swarf containing water has the tendency to form a highly resistant foam on the surface of the liquid. In order to prevent environment pollution it was necessary to eliminate such foam before discharging such water into the sewage system. Heretofore such foam elimination was carried out with cumbersome expensive equipments which did not give economically satisfactory results.